<!DOCTYPE HTML>
<html>
<head>
  <title>Test that we don't get unnecessary repaints with fixed backgrounds</title>
  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/paint_listener.js"></script>
  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
</head>
<!-- Need a timeout here to allow paint unsuppression before we start the test -->
<body onload="setTimeout(startTest,0)" style="background:url(blue-32x32.png) top left no-repeat fixed; background-size: 100px 2000px; overflow:hidden;">
<div style="height: 2048px"></div>

<pre id="test">
<script type="application/javascript">
SimpleTest.waitForExplicitFinish();

var utils = window.QueryInterface(Components.interfaces.nsIInterfaceRequestor).
               getInterface(Components.interfaces.nsIDOMWindowUtils);

function startTest() {
  // Do a scroll to ensure we trigger activity heuristics.
  document.documentElement.scrollTop = 1;
  waitForAllPaintsFlushed(function () {
    document.documentElement.scrollTop = 0;
    waitForAllPaintsFlushed(function () {
      // Clear paint state and scroll down
      utils.checkAndClearPaintedState(document.documentElement);
      document.documentElement.scrollTop = 100;
      waitForAllPaintsFlushed(function () {
        // Make sure nothing painted
        var painted = utils.checkAndClearPaintedState(document.documentElement);
        is(painted, false, "Fixed background should not have been painted when scrolled");
        SimpleTest.finish();
      });
    });
  });
}
</script>
</pre>
</body>
</html>
